TWI285828B - Method for switching audio signals and the apparatus of the same - Google Patents

Abstract

The method and apparatus are provided for several audio signal processing apparatuses to share at least one audio output device. Several audio signals sent from the audio signal processing apparatuses are received. The audio signals are shifted the DC levels thereof. One of the adjusted audio signals is then selected for transmitting to the audio output device. After that, the selected audio signal is re-adjusted the DC level thereof.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to a switching device, and more particularly to an audio signal switching device and method therefor. [Prior Art] Due to the rapid development of information technology, the application of computers and their peripheral products is quite popular. Computer users usually use a mouse and keyboard to input peripheral devices to operate the computer. The computer monitors the status of the computer on the monitor or uses the voice indication by monitoring _____ ” ^ side device to enable the computer user to master the computer at any time. Instant conditions. Sometimes, in order to meet different needs, users may have more than one computer to handle different kinds of things. Traditionally, each computer should be equipped with a set of input/output peripherals such as keyboard and slide. Rats, monitors and speakers, but this configuration is a waste of money and space. In the large system operators or small and medium-sized enterprises, there are thousands or at least several servos. For each server, monitors, keyboards and mice are required for management. 2 When using the server, it is rare to use these inputs\rounding peripherals, most of them. When the main knives are used, the server does not need to be controlled by the administrator. Therefore, in this kind of obstacle, the mother server uses an individual one.

Group input / output peripheral device 杲z v A anti-clothing is unnecessary and not synthetic, and it will cause space waste. 1 Then a switching device uses a set of input/output peripherals to 1285828

Managing 多 4 _ ^ on multiple computers solves this problem. The use of switching devices not only solves the cost of closed, but also solves the problem of equipment and space, and can also overcome the compatibility problems of different interfaces. . The switching device of I♦ does not perform well when processing audio signal switching. For example, the direct current levels of the sound (4) output by each sound card are not the same. If the audio signals of different processing devices have different DC levels, it is easy to generate pops when they switch. Moreover, if other high-power input/output peripheral devices are switched, a large amount of power consumption at this time causes the DC level in the entire switching device to float, which causes an interference sound of the audio signal. In addition, conventional switching devices often use mechanical relays to switch. However, the mechanical switching device has a limited mechanical life, and the durability is not south, and it is easy to generate a bouncing fire when switching, and the switching device malfunctions or even generates a surge to damage the precision components in the computer. SUMMARY OF THE INVENTION Therefore, the object of the present invention is to provide an audio signal switching method of 'adjusting the DC level of an audio signal, so that the DC level of the audio signal at both ends of the multiplexer is kept fixed, so as to avoid the cause of switching the audio signal. A problem that produces a popping sound due to a level difference or an interfering sound due to other high-power loads. Another object of the present invention is to provide an audio signal switching apparatus for switching audio signals by using a DC level filtering circuit and a DC level adjusting circuit in combination with a chip, in addition to avoiding the occurrence of popping and interfering sounds, 1285828, ("The replacement page, -1, and I long switch device life, to prevent the occurrence of bounce sparks or surges to damage the device. According to the above object of the present invention, an audio signal switching method = and eight devices are proposed. The plurality of first audio signal processing devices share at least one frequency Λ5 tiger output device. The method of the present invention first receives the first audio signals, and the plurality of first audio signals transmitted by the number processing device, and adjusts the The DC level of the first audio signal is to a first predetermined value, and a plurality of first audio signals are obtained. Then, one of the second audio signals is selected, and then the DC of the selected second audio signal is adjusted. Leveling to the first predetermined value to obtain a third audio signal. The apparatus of the present invention includes a plurality of first pre-processing devices connected to the first An audio signal processing device, a first multiplexer switcher and at least one first post-processing device, each of the first pre-processing devices receiving a first audio signal from the connected first audio signal processing device, and adjusting The first audio signal is obtained by the DC signal of the first audio signal to a first predetermined value, and the second multiplexer receives the second audio signals from the first pre-processing devices, and selects the One of the second audio signals is outputted. The first post-processing device receives the selected second audio signal and adjusts the selected DC frequency of the second audio signal to the first predetermined value A third audio signal. According to a preferred embodiment of the present invention, each of the first pre-processing devices includes a first DC level filtering circuit and a first DC level adjusting circuit. The level filtering circuit filters out the DC level of the first audio signal. The first DC level adjustment circuit from the first DC level filtering circuit 1285828

Receiving the first audio signal that has filtered the DC level, and adjusting the DC level of the first audio frequency that has filtered out the DC level to the first predetermined value. The first post-processing device includes a second DC level adjustment circuit and a second DC level filter circuit. The second DC level adjustment circuit receives the second audio signal from the first multiplex switch, and adjusts the DC level of the second audio signal to the first predetermined value. The second DC level filtering circuit receives the second audio signal of the adjusted DC level from the second DC level adjustment circuit and filters out the DC level of the second audio signal with the adjusted DC level. For output to the audio signal output device. The first DC level filtering circuit includes a first capacitor, and the second DC level filtering and dividing circuit includes a second capacitor. The first DC level adjustment circuit includes a first resistor and a second resistor. One end of the first resistor is electrically connected to a high potential. The other end of the first resistor and the second resistor are electrically connected. Connected, and the other end of the second resistor is connected to the low potential, and the second DC level adjusting circuit includes a third resistor and a fourth resistor. One end of the third resistor is electrically connected to the high potential The other end of the second resistor is electrically connected to one end of the fourth resistor, and the other end of the fourth resistor is electrically connected to the low potential. Secondly, the other end of the first resistor is further electrically connected to the first DC level circuit and the first multiplexer and the other end of the third resistor is further connected to the second DC level filter. In addition to the circuit and the first multiplex switch _ t connection. Furthermore, in a preferred embodiment of the present invention, the resistance of the first resistor 盥 the three resistors is equal, and the second resistor is equal to the fourth resistor: the electrical value. The first multiplexer switch is a multiplexed switching chip, and the high power 1285828

The bit is provided via a voltage regulator and the low potential is a ground potential. When the first multiplexer is a positive voltage multiplexer switching chip, the resistance of the first resistor is less than the resistance of the second resistor, and the resistance of the third resistor is less than the resistance of the fourth resistor When the first multiplexer switch is a positive/negative voltage multiplexer switching chip, the resistance value of the first resistor is equal to the resistance value of the second resistor' and the resistance value of the third resistor is equal to the resistance of the fourth resistor value. According to another preferred embodiment of the present invention, the audio signal switching device of the present invention is also applicable to a plurality of second audio signal processing devices sharing at least one audio signal input device. At this time, the audio signal switching device further includes a second pre-processing device, a second multiplex switch, and a plurality of second post-processing devices. The second pre-processing device is connected to the audio signal input device, receives a fourth audio signal from the audio signal input device, and adjusts the DC level of the fourth audio signal to a second predetermined value to obtain a fifth audio signal. . The second multiplexer receives the fifth audio signal from the second pre-processing device. a plurality of second post-processing devices, wherein the second multiplexer selects to input the fifth audio signal, and each of the second post-processing devices adjusts the fifth audio signal after receiving the fifth audio signal A sixth audio signal is obtained by directing the DC level to the predetermined value. The switching device of the invention adds a set of DC level filtering circuit and a DC level adjusting circuit at both ends of the multiplexer switch, and adjusts the DC level after the audio signal input switching device, and passes the audio signal through After switching the switch, adjust the DC level again so that the DC level of the audio signal at both ends of the multiplexer remains fixed to avoid switching the audio frequency 1285828

When the number is generated, the popping sound is generated due to the level difference, and the interference sound is generated due to the load of other power consumption. Furthermore, the present invention can use a multiplexed switching chip to switch the audio signal, thereby extending the service life of the cutting and negative switching devices, preventing the occurrence of bounce sparks or generating surges and damaging the device. [Embodiment] Fig. 1 is a schematic view showing a case in which the embodiment of the present invention is used in a continuous manner. As shown in Fig. 1, the audio signal processing devices i6a, 6i, 6c, and 106d share at least one audio signal output device 102 via the audio signal switching device of the present invention. The audio signal processing device i〇6a, 106b, 1〇6c or 106d is, for example, a sound card, a musical instrument digital interface (Musicai)

Instrument Digital Interface, MIDI) Split, stereo, audio source or TV. The audio signal output device 102 is, for example, a racquet, an earphone, a monitor or an amplifier, or even an input of other audio signal processing devices. Figure 2 is a flow chart showing a preferred embodiment of the method of the present invention. The audio nickname switching device 1 〇4 selects one of the audio signal processing devices 106a, 16b, 106c and 106d with a multiplexer switch, and allows the selected audio signal processing device to be output by the audio signal. The device 丨〇 2 outputs an audio signal. The method of the present invention first receives the audio signals transmitted by the audio signal processing devices 106a, 106b, 106() and 106d (step 2〇2). The DC levels of the audio signals are removed (step 2〇4), and the DC levels of the audio signals whose DC levels have been filtered are adjusted (steps 2〇6). After the audio signal passes through the multiplexer (step 208), the DC level of the selected audio signal is adjusted again (step 216), and the re-adjusted DC 1285828 ft%! The direct current level of the audio signal of the page level is replaced. Fig. 3 is a partial schematic diagram showing the audio signal switching device of the i-th figure. As described above, the audio signal switching device of the present invention is used to connect a plurality of The audio signal processing device and the at least-audio signal output device. In order to clearly explain the contents of the present invention, both ends of the number switching device 1〇4 shown in FIG. 3 are only shown at the respective edges—the audio signal processing device 1〇 °6 and an audio signal output device 1〇2. The audio signal switching device 丨〇4 of the present invention comprises a plurality of pre-processing devices, each of which is connected to a plurality of audio signal processing devices, and in FIG. 3, only a single group is processed first. The device 306 and the audio signal processing device 106 are representative. The audio signal switching device 1 亦4 also includes at least one post-processing device 302' for connecting the audio signal output device 1〇2, and by multiplexing The benefit 3 0 4 controls the path switch between the pre-processing device 3 0 6 and the post-processing device 3 〇 2, thus allowing an audio signal processing device 丨〇 6 to output an audio signal by the audio signal output device 102. The audio signal is from the audio signal After the processing device 106 inputs the audio signal switching device 104, the first DC level filtering circuit 342 filters and removes the DC level of the audio signal by using the capacitor 348. Then, the first DC level adjusting circuit 3 3 2 adjusts In this embodiment, the first DC level adjustment circuit 332 includes a first resistor 336 and a second resistor 334 for adjusting the DC level of the audio signal by the principle of resistor division. One end of the first resistor 336 is electrically connected to a high potential 356, and the other end of the first resistor 336 is electrically connected to one end of the second resistor 334, and the other end of the second resistor 334 is connected to a low potential. 354. 11 1285828 日修沐) The audio signal that is being adjusted to the DC level is replaced by the path arranged by the multiplexer 3〇4 and sent to the post-processing device 3〇2, in the post-processing device. 3 The second DC level adjustment circuit 312 is adjusted to its DC level again in 〇2. Similarly, in this embodiment, the second DC level adjustment circuit 312 includes a third resistor 316 and a fourth resistor 314 for adjusting the DC level of the audio signal by the principle of resistor division. One end of the third resistor 316 is electrically connected to the south potential 356, and the other end of the third resistor 316 is electrically connected to one end of the fourth resistor 314, and the other end of the fourth resistor is connected to the low potential 354. Finally, after the audio signal of the DC level is adjusted again, the second DC level filtering circuit 322 is used to filter the DC level of the audio signal by using the capacitor 328. The conventional audio signal switching device is because the multiplex switch switches the path between the different processing devices and the post-processing device, and the DC levels of the audio signals at both ends are different, resulting in the generation of pops. The invention utilizes a combination of two DC level filtering circuits and a DC level adjusting circuit 342/332 and 312 to fix the DC level of the audio signal at both ends of the multiplexer 3()4, thus avoiding switching. When the audio signal is generated, the pop sound is generated due to the level difference. In the preferred embodiment, the first resistor 336 and the third resistor 316 are electrically connected to the same high potential 356 (3·3 volts), and the second resistor 334 and the fourth resistor 314 are electrically connected. Connected to the same low potential 35 - 4 (ground) 'so 'the resistance of the first-resistor 336 and the third resistor 316 are equal' and the resistance values of the second resistor 334 and the fourth resistor 314 are equal. In this way, the multiplexed switching of the DC level of the audio signal of H 3〇4 (4) can maintain the solid 12 1285828 ^ 〇 repair 8 positive replacement page L ---- iirfii. In order to prolong the service life of the switching device, and prevent bounce sparks or generate The spurs damage the device. In the preferred embodiment, the multiplexer 304 selects a multiplexed switching die. The multiplexed switching wafer can be a positive voltage multiplexed switching wafer driven with a positive voltage, or a positive voltage multiplexed switching wafer driven with a positive and negative voltage. The positive voltage multiplex switching chip has a small volume, and the adjustment function of the audio signal DC level of the present invention is suitable for a small volume easy-to-use audio signal switching device. Positive and negative voltage multiplexed switching chips have better sound quality and can avoid the problem of crosstalk (cr〇sstalk), and are suitable for high-quality 声-bit quality audio signal switching devices. When the multiplexer switch 304 is a positive voltage multiplexer switching chip, the resistance value of the first resistor 336 is smaller than the resistance value of the second resistor 334, and the resistance value 316 of the third resistor is smaller than the resistance value of the fourth resistor 314. According to a preferred embodiment of the present invention, the galvanic lifetime of the first resistor 336 and the third resistor 316 is 5.6 kilohms (kQ), and the resistance values of the second resistor 334 and the fourth resistor 314 are 1〇. Thousand ohms, so that the DC level adjustment of the audio signal at the left and right ends of the multiplexer switch 4 can be fixed to about 2 volts. When the first multiplexer is a positive/negative voltage multiplexer switching chip, the resistance of the first resistor 336 is equal to the resistance of the second resistor 334, and the resistance of the third resistor 316 is equal to the resistance of the fourth resistor 314. value. According to the example of this X-month, the resistance of the first resistor 336, the second resistor 334, the second resistor 316 and the fourth resistor 314 is (7) kilo ohms. The DC level adjustment of the audio signal at the left and right ends of the multiplexer switch 3〇4 is fixed to about 〇Vot. 13 1285828 p__ ?5年ϋ月[日修(或)正换页 In this preferred embodiment, the audio signal switching device of the present invention is coupled

And a computer switcher (Keyboard-Video-Mouse Switch; KVM

Among the switches, this switcher allows users to manage devices that control multiple computers using one or more sets of input/output peripherals. Figure 4 is a block diagram showing a preferred embodiment of a computer switcher having an audio signal switching device of the present invention. The computer switcher 404 is responsible for switching between a plurality of computers 406 and at least one client 402. In the preferred embodiment, the device of the present invention is powered by a voltage in order to prevent the interference of the high and low potentials in the computer switcher caused by the load of other south power consuming devices, such as an optical mouse. A voltage regular provides a stable high potential and its low potential is tied to a ground potential. Figure 5 is a schematic view showing another preferred embodiment of the present invention in actual use. In the preferred embodiment, the user can selectively receive the audio signal processing device 106a, 1〇6b, 1〇6c or l by using the audio signal output device 1〇2 by the audio signal switching device 504. In addition to the audio signal transmitted by 〇6d, another audio signal can be simultaneously used by the same audio signal switching device 504, using an audio signal input device 5〇2, such as a microphone or an audio signal input device, to transmit another audio signal. The audio signal processing means 106a, l6b, l6c, l6d or other audio signal processing means 106 are input. Fig. 6 is a partial schematic view showing the audio signal switching device of Fig. 5. The following only explains the portion of the audio signal input by the user, and the other portions are the same as the audio signal switching device shown in Fig. 3. As described above, the audio signal switching device of the present invention is used to connect a plurality of audio frequencies 14 1285828 "― ***,··· ΊΤ _ 丨 · * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * .................. </ br> is replacing the page signal processing device and at least one audio signal input device. In order to clearly explain the contents of the present invention, The audio signal switching device 5〇4 shown in FIG. 6 only shows an audio signal processing device 〇6 and an audio signal input device 502. The audio signal switching device 5〇4 of the present invention includes a plurality of The post-processing devices are respectively connected to a plurality of audio signal processing devices, and are represented by a single group of post-processing devices 602 and audio signal processing devices 106 in Fig. 6. The audio signal switching device 504 also includes at least one pre-processing device 606. For connecting the audio signal input device 5〇2, and controlling the path switch between the pre-processing device 606 and the post-processing device 6〇2 by the multiplexer 604, thus allowing the audio signal input device 5〇2 to input the audio signal to a certain An audio signal processing device 1〇6. Audio signal After the audio signal switching device 504 is input from the audio signal input device 502, for example, a microphone, since the frequency signal received by the general microphone is very weak, the high potential 656 is first amplified with the resistor 662. Then, the first DC standard is used. The bit filtering circuit 642 filters the DC level of the audio signal by using a capacitor 648. Next, the first DC level adjusting circuit 632 adjusts the DC level of the audio signal. In this embodiment, the first straight The current level adjustment circuit 632 includes a first resistor 636 and a second resistor 634, and adjusts the DC level of the audio signal by using a voltage division principle. One end of the first resistor 636 is electrically connected to a high potential 656. The other end of the first resistor 636 is electrically connected to one end of the second resistor 634, and the other end of the second resistor 634 is connected to a low potential 654. 15 1285828 ? 5 years) Months (X) The audio signal of the replacement page/week-weeked DC level is passed through the path of the multiplexer 6〇4 female platoon and then sent to the post-processing device 602 corresponding to the audio signal processing device 100 for post-processing. Device 602 The second DC level adjustment circuit 612 is further adjusted by the second DC level adjustment circuit 612. Similarly, in this embodiment, the second DC level adjustment circuit 612 includes a third resistor 616 and a fourth resistor 614. The principle of the pressure adjusts the straight level of the audio signal. One end of the third resistor 616 is electrically connected to the high potential, and the other end of the third resistor 616 is electrically connected to one end of the fourth resistor 6 and the first The other end of the four resistor 614 is connected to the low potential 654. _ Finally, after the audio signal of the DC level is adjusted again, the first DC level filtering circuit 622 is used, and the capacitor 628 is used to filter the DC level of the audio signal.

Similarly, when the multiplexer switch 6〇4 is a positive voltage multiplexed switching chip, the resistance value of the first resistor 636 is smaller than the resistance value of the second electrical ρ and (4), and the resistance value 616 of the second resistor is less than the fourth. The resistance value of the resistor. According to a preferred embodiment of the present invention, the resistance of the first resistor 636 and the third resistor is 15 kilohms (10), and the resistance of the fourth resistor 426 is 27 kilohms. When the first multiplexer is a positive/negative voltage multiplexer, the resistance of the first resistor 636 is equal to the resistance of the second resistor 634 and the resistance of the third resistor 616 is equal to the resistance of the fourth resistor 614. . According to another preferred embodiment of the present invention, the resistance values of the first resistor 636, the second e resistor "4, the third resistor 616, and the fourth resistor 614 are: kilo ohms. 16 1285828

^年二伊月^曰修(j() is replacing page I, $. However, the present invention has been disclosed in a preferred embodiment as above, but it is not intended to limit the invention, and anyone skilled in the art can not The spirit of the invention: In the scope of the invention, the scope of the invention is defined by the scope of the appended claims. And other purposes, features, and advantages

The following is a detailed description of the preferred embodiment, and the following is a detailed description of the following: FIG. 1 is a schematic view of the preferred embodiment of the present invention in actual use; Figure 2 is a flow chart showing a preferred embodiment of the method of the present invention, and Figure 3 shows the relationship! Part of the audio signal switching device of the figure;

4 is a schematic view showing a preferred embodiment of a computer switch having the audio signal switching device of the present invention; and FIG. 5 is a schematic view showing another preferred embodiment of the present invention in actual use; Figure 6 is a partial schematic diagram of the audio signal switching device of Figure 5 [simple description of the component representative symbol] 102: audio signal output device 17 1285828 ^ 凡日修 (table) is being replaced page 104: audio signal switching device 106, 106a, 106b, 106c, 106d: audio signal processing device 202, 204, 206, 208, 214, 216: step 302: post-processing device 304: multiplexer switch 306: first processing device 3 12: second DC standard Bit adjustment circuit 314: fourth resistor 316: third resistor 322: second DC level filter circuit 328: capacitor 332: first DC level adjustment circuit 334: second resistor 336: first resistor 342: first DC level filtering circuit 348: capacitor 354: low potential 356: high potential 402: user terminal 404: computer switcher 406: multiple computers 502: audio signal input device 504: audio signal switching device 602: post processing device 604 : multiplexer switch 606: First processing device 612: second DC level adjusting circuit 614: fourth resistor 616: third resistor 622: second DC level filtering circuit 628: capacitor 632: first DC level adjusting circuit 634: second resistor 636: first resistor 642: first DC level filtering circuit 18 1285828 monthly force correction (&amp;) is replacing page 648 · capacitor 654 · low potential 656 · high potential

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Claims (1)

1285828 Year z 刺日修 (X) 正本, patent application scope i. A frequency signal switching device for a plurality of first-audio processing devices to share at least one audio signal in the Aussie JU device at least: "Μ output device, The audio signal is switched to a plurality of first-first processing devices, and the first audio signal processing is connected to the first audio processing unit, wherein each of the first processing devices receives a first audio signal from the connected signal processing device, and adjusts the Receiving the first audio signal from the first pre-processing devices, and selecting the DC frequency of the first audio frequency to the -th-value to obtain the second audio signal; One of the second audio signals is for output, and a first post-processing device receives the selected second audio signal and adjusts a DC level of the selected second audio signal to the first predetermined The audible signal switching device of claim 1, wherein each of the first pre-processing devices comprises a first DC level filtering circuit And the first DC level adjustment circuit receives the first audio signal that has filtered the DC level, and the first DC level adjustment circuit is configured to filter the DC level of the first audio signal, And adjusting the DC level of the first audio signal that has filtered the DC level to the first predetermined value, and the first post-processing device includes a second DC level adjustment circuit, from the first multiplex 20 1285828 Switching Is receives the selected second audio signal, and adjusts the selected DC frequency of the second audio signal to the first predetermined value, and a second DC level filtering circuit from the second DC standard The bit adjustment circuit receives the second audio signal of the adjusted DC level, and filters out the DC level of the first audio signal with the adjusted DC level. 3. The audio signal switching as described in claim 2 The device, wherein the first DC level filtering circuit comprises a second DC level filtering circuit comprising a second capacitor. 4 4. The audio signal switching device according to claim 2, wherein the -Multiplex switcher is more than one Switching the chip. For example, please refer to the 讯 讯 切换 : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : The other end of the first resistor is electrically connected to S (f) of the second electric resistor, and the second circuit includes a third resistor and a fourth resistor: the abundance 6 is electrically connected to the high potential.嗲 _ ^ — one end of the resistor - the end of the electrical I: the other end of the I resistor is connected to the fourth resistor. Another 'with the low potential electrical 6 · as described in the scope of claim 5 of the audio signal switching The device is connected to the other end of the first resistor and the first multiplexer is electrically connected to the device: 21. In addition to the circuit and the first-multiplex switching, such as the switching device of the patent application range, and the audio frequency ti described in the item f, j. φ ^, one or two steps, a resistance value, a resistance, and the first The resistance of the four resistors is equal. «•If the audio signal is as described in item 5 of the patent application scope, the resistance of the first resistor is used when the first multiplex switch is changed to a positive voltage multiplex switching crystal H. The value is small, and the resistance value of the first resistor is less than the resistance value of the fourth resistor. 9. The audio signal switching device of claim 5, wherein when the first multiplexer is a positive/negative voltage multiplexed switching chip, the resistance of the first resistor is equal to the resistance of the second resistor. And a resistance value of the second resistor is equal to a resistance value of the fourth resistor. 10. The audio signal switching device of claim 5, wherein the high potential is provided via a voltage regulator and the low potential is a ground potential. 11: The audio signal switching device 22 1285828, wherein the audio signal switching device also shares a plurality of audio signal input devices, wherein the audio signal switching device further comprises at least one audio signal input device. The second pre-processing device is connected to the audio signal input device, wherein the second pre-processing device receives a fourth audio signal from the audio signal input device, and adjusts the DC level of the fourth audio signal to a first a second predetermined value to obtain a fifth audio signal; a second multiplex switch to receive the fifth audio signal from the second pre-processing device; and a plurality of second post-processing devices for the second multiplex The switch selects to input the fifth audio signal, and each of the second post-processing devices adjusts the DC level of the fifth audio signal to the second predetermined value after receiving the fifth audio signal, to obtain a first Six audio signals. 12 - an audio signal switching method, wherein a plurality of first audio signal processing devices share an audio signal output device, and the audio signal switching method includes at least: _ receiving a plurality of the first audio signal processing devices An audio signal; adjusting a DC level of the first audio signal to a first predetermined value to obtain a plurality of second audio signals; selecting the second audio signals; adjusting the selected second audio signal The DC level is to the first predetermined value to obtain a third audio signal. The method of switching the audio signal according to claim 12, wherein the method for switching the audio signal further comprises: filtering out the DC signals before the whole of the first audio signals. The DC level of the first audio signal; and after adjusting the DC level of the second audio signal, filtering the DC level of the third audio signal. The audio signal switching as described in claim 13 of the patent scope The DC level of the two audio signals is filtered by a first capacitor, and the DC level of the third audio signal is filtered by a second capacitor. The audio signal switching method of the item, wherein the selected second audio signal is selected by a multiplexed switching chip. 16. The audio signal switching party according to claim 13 of the patent application scope has been filtered out. The DC level of the first audio signal of the DC level is adjusted by a first resistor and a second resistor, wherein one end of the first resistor is electrically connected to a high potential, and the first resistor is another The terminal is electrically connected to one end of the first resistor, and the other end of the second resistor is connected to a low potential, and the DC level of the selected second audio signal is a third resistor and a fourth resistor To adjust, wherein one end of the third resistor 24 1285828 is connected to the other end of the local potential - the fourth resistor is connected to the fourth resistor. The other end of the resistor and the low potential electrical method, Γ φ Γ 专利 patent scope The audio signal switching side-resistor 盥'&quot; of the 16th item is equal to the resistance value of the third resistor, and the resistance value of the first resistor and the fourth resistor is ##, , j8丄The audio signal switching mentioned in the range of item 16 is the same as the second electric resistance The resistance value of the resistor is less than the resistance of the fourth resistor. The audio signal switching method described in item 16 of the patent scope of the application is to use the positive and negative voltage multiplex switching chips to select the second audio frequencies. The resistance value of the first resistor The resistance value of the second resistor is 'and the resistance value of the third resistor is equal to the resistance of the fourth resistor, 20·== please call the audio signal switching method described in item 16 of the patent range, wherein the zeta potential The audio signal switching method according to claim 12, wherein the audio signal switching method is also provided for multiple seconds. The audio signal processing device shares an audio signal input device, and the audio signal switching method further includes: receiving a fourth audio signal transmitted by the audio signal input device; adjusting a DC level of the fourth audio signal to a second predetermined value And obtaining a fifth audio signal; selecting one of the second audio signal processing devices for inputting the fifth audio signal; and adjusting the fifth audio frequency after selecting one of the second audio signal processing devices The DC level of the signal is to the second predetermined value to obtain a sixth audio signal. 26